1 files changed, 90 insertions, 73 deletions

diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 4a7f2a54659..c3835c7536c 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -1,4 +1,4 @@
-/* Copyright (c) 2000, 2010 Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -557,24 +557,27 @@ Item *Item_sum::set_arg(uint i, THD *thd, Item *new_val)
 
 int Item_sum::set_aggregator(Aggregator::Aggregator_type aggregator)
 {
-  if (aggr)
+  /*
+    Dependent subselects may be executed multiple times, making
+    set_aggregator to be called multiple times. The aggregator type
+    will be the same, but it needs to be reset so that it is
+    reevaluated with the new dependent data.
+    This function may also be called multiple times during query optimization.
+    In this case, the type may change, so we delete the old aggregator,
+    and create a new one.
+  */
+  if (aggr && aggregator == aggr->Aggrtype())
   {
-    /* 
-      Dependent subselects may be executed multiple times, making
-      set_aggregator to be called multiple times. The aggregator type
-      will be the same, but it needs to be reset so that it is
-      reevaluated with the new dependent data.
-    */
-    DBUG_ASSERT(aggregator == aggr->Aggrtype());
     aggr->clear();
     return FALSE;
   }
+
+  delete aggr;
   switch (aggregator)
   {
   case Aggregator::DISTINCT_AGGREGATOR:
     aggr= new Aggregator_distinct(this);
     break;
-
   case Aggregator::SIMPLE_AGGREGATOR:
     aggr= new Aggregator_simple(this);
     break;
@@ -1143,17 +1146,13 @@ Item_sum_hybrid::fix_fields(THD *thd, Item **ref)
 
   switch (hybrid_type= item->result_type()) {
   case INT_RESULT:
-    max_length= 20;
-    break;
   case DECIMAL_RESULT:
+  case STRING_RESULT:
     max_length= item->max_length;
     break;
   case REAL_RESULT:
     max_length= float_length(decimals);
     break;
-  case STRING_RESULT:
-    max_length= item->max_length;
-    break;
   case ROW_RESULT:
   default:
     DBUG_ASSERT(0);
@@ -1197,8 +1196,10 @@ void Item_sum_hybrid::setup_hybrid(Item *item, Item *value_arg)
   value= Item_cache::get_cache(item);
   value->setup(item);
   value->store(value_arg);
+  arg_cache= Item_cache::get_cache(item);
+  arg_cache->setup(item);
   cmp= new Arg_comparator();
-  cmp->set_cmp_func(this, args, (Item**)&value, FALSE);
+  cmp->set_cmp_func(this, (Item**)&arg_cache, (Item**)&value, FALSE);
   collation.set(item->collation);
 }
 
@@ -1326,27 +1327,11 @@ void Item_sum_sum::fix_length_and_dec()
 bool Item_sum_sum::add()
 {
   DBUG_ENTER("Item_sum_sum::add");
-  bool arg_is_null;
   if (hybrid_type == DECIMAL_RESULT)
   {
-    my_decimal value, *val;
-    if (aggr->use_distinct_values)
-    {
-      /* 
-        We are aggregating distinct rows. Get the value from the distinct 
-        table pointer
-      */
-      Aggregator_distinct *daggr= (Aggregator_distinct *)aggr;
-      val= daggr->table->field[0]->val_decimal (&value);
-      arg_is_null= daggr->table->field[0]->is_null();
-    }
-    else
-    {
-      /* non-distinct aggregation */
-      val= args[0]->val_decimal(&value);
-      arg_is_null= args[0]->null_value;
-    }
-    if (!arg_is_null)
+    my_decimal value;
+    const my_decimal *val= aggr->arg_val_decimal(&value);
+    if (!aggr->arg_is_null())
     {
       my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs + (curr_dec_buff^1),
                      val, dec_buffs + curr_dec_buff);
@@ -1356,25 +1341,8 @@ bool Item_sum_sum::add()
   }
   else
   {
-    double val;
-    if (aggr->use_distinct_values)
-    {
-      /* 
-        We are aggregating distinct rows. Get the value from the distinct 
-        table pointer
-      */
-      Aggregator_distinct *daggr= (Aggregator_distinct *)aggr;
-      val= daggr->table->field[0]->val_real ();
-      arg_is_null= daggr->table->field[0]->is_null();
-    }
-    else
-    {
-      /* non-distinct aggregation */
-      val= args[0]->val_real();
-      arg_is_null= args[0]->null_value;
-    }
-    sum+= val;
-    if (!arg_is_null)
+    sum+= aggr->arg_val_real();
+    if (!aggr->arg_is_null())
       null_value= 0;
   }
   DBUG_RETURN(0);
@@ -1472,6 +1440,45 @@ Aggregator_distinct::~Aggregator_distinct()
 }
 
 
+my_decimal *Aggregator_simple::arg_val_decimal(my_decimal *value)
+{
+  return item_sum->args[0]->val_decimal(value);
+}
+
+
+double Aggregator_simple::arg_val_real()
+{
+  return item_sum->args[0]->val_real();
+}
+
+
+bool Aggregator_simple::arg_is_null()
+{
+  return item_sum->args[0]->null_value;
+}
+
+
+my_decimal *Aggregator_distinct::arg_val_decimal(my_decimal * value)
+{
+  return use_distinct_values ? table->field[0]->val_decimal(value) :
+    item_sum->args[0]->val_decimal(value);
+}
+
+
+double Aggregator_distinct::arg_val_real()
+{
+  return use_distinct_values ? table->field[0]->val_real() :
+    item_sum->args[0]->val_real();
+}
+
+
+bool Aggregator_distinct::arg_is_null()
+{
+  return use_distinct_values ? table->field[0]->is_null() :
+    item_sum->args[0]->null_value;
+}
+
+
 Item *Item_sum_count::copy_or_same(THD* thd)
 {
   return new (thd->mem_root) Item_sum_count(thd, this);
@@ -1577,7 +1584,7 @@ bool Item_sum_avg::add()
 {
   if (Item_sum_sum::add())
     return TRUE;
-  if (!args[0]->null_value)
+  if (!aggr->arg_is_null())
     count++;
   return FALSE;
 }
@@ -1893,7 +1900,10 @@ double Item_sum_hybrid::val_real()
   DBUG_ASSERT(fixed == 1);
   if (null_value)
     return 0.0;
-  return value->val_real();
+  double retval= value->val_real();
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == 0.0);
+  return retval;
 }
 
 longlong Item_sum_hybrid::val_int()
@@ -1901,7 +1911,10 @@ longlong Item_sum_hybrid::val_int()
   DBUG_ASSERT(fixed == 1);
   if (null_value)
     return 0;
-  return value->val_int();
+  longlong retval= value->val_int();
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == 0);
+  return retval;
 }
 
 
@@ -1910,7 +1923,10 @@ my_decimal *Item_sum_hybrid::val_decimal(my_decimal *val)
   DBUG_ASSERT(fixed == 1);
   if (null_value)
     return 0;
-  return value->val_decimal(val);
+  my_decimal *retval= value->val_decimal(val);
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == NULL);
+  return retval;
 }
 
 
@@ -1920,7 +1936,10 @@ Item_sum_hybrid::val_str(String *str)
   DBUG_ASSERT(fixed == 1);
   if (null_value)
     return 0;
-  return value->val_str(str);
+  String *retval= value->val_str(str);
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == NULL);
+  return retval;
 }
 
 
@@ -1975,11 +1994,11 @@ Item *Item_sum_min::copy_or_same(THD* thd)
 bool Item_sum_min::add()
 {
   /* args[0] < value */
-  int res= cmp->compare();
-  if (!args[0]->null_value &&
-      (null_value || res < 0))
+  arg_cache->cache_value();
+  if (!arg_cache->null_value &&
+      (null_value || cmp->compare() < 0))
   {
-    value->store(args[0]);
+    value->store(arg_cache);
     value->cache_value();
     null_value= 0;
   }
@@ -1998,11 +2017,11 @@ Item *Item_sum_max::copy_or_same(THD* thd)
 bool Item_sum_max::add()
 {
   /* args[0] > value */
-  int res= cmp->compare();
-  if (!args[0]->null_value &&
-      (null_value || res > 0))
+  arg_cache->cache_value();
+  if (!arg_cache->null_value &&
+      (null_value || cmp->compare() > 0))
   {
-    value->store(args[0]);
+    value->store(arg_cache);
     value->cache_value();
     null_value= 0;
   }
@@ -2244,7 +2263,7 @@ void Item_sum_avg::reset_field()
 
 void Item_sum_bit::reset_field()
 {
-  reset();
+  reset_and_add();
   int8store(result_field->ptr, bits);
 }
 
@@ -3057,6 +3076,7 @@ Item_func_group_concat(Name_resolution_context *context_arg,
       order_item->item= arg_ptr++;
     }
   }
+  memcpy(orig_args, args, sizeof(Item*) * arg_count);
 }
 
 
@@ -3267,7 +3287,6 @@ Item_func_group_concat::fix_fields(THD *thd, Item **ref)
   if (check_sum_func(thd, ref))
     return TRUE;
 
-  memcpy (orig_args, args, sizeof (Item *) * arg_count);
   fixed= 1;
   return FALSE;
 }
@@ -3423,8 +3442,6 @@ String* Item_func_group_concat::val_str(String* str)
 
 void Item_func_group_concat::print(String *str, enum_query_type query_type)
 {
-  /* orig_args is not filled with valid values until fix_fields() */
-  Item **pargs= fixed ? orig_args : args;
   str->append(STRING_WITH_LEN("group_concat("));
   if (distinct)
     str->append(STRING_WITH_LEN("distinct "));
@@ -3432,7 +3449,7 @@ void Item_func_group_concat::print(String *str, enum_query_type query_type)
   {
     if (i)
       str->append(',');
-    pargs[i]->print(str, query_type);
+    orig_args[i]->print(str, query_type);
   }
   if (arg_count_order)
   {
@@ -3441,7 +3458,7 @@ void Item_func_group_concat::print(String *str, enum_query_type query_type)
     {
       if (i)
         str->append(',');
-      pargs[i + arg_count_field]->print(str, query_type);
+      orig_args[i + arg_count_field]->print(str, query_type);
       if (order[i]->asc)
         str->append(STRING_WITH_LEN(" ASC"));
       else